The present invention relates to a wire-driving device for a window regulator (hereinafter referred to as "driving device"), and more particularly to a driving device which has a reduced whole thickness.
Until now, a window regulator, e.g. a window regulator shown in FIG. 6, is employed as a means for automatically opening and closing a window of an automobile, a building, or the like. The window regulator shown in FIG. 6 comprises a driving device 80 and a driven device 82. The driving device 80 changes a rotational motion of a motor 10 into a linear motion of two wires 41, 42 ends of which are engaged to a circumference of a pulley 6 and which are wound in the opposite directions with each other. The change of the motion is obtained by transmitting the above rotational motion to a pulley 6, winding one of the wires 41, 42 round the pulley 6 and unwinding the other wire from the pulley 6. As shown in FIG. 6 the driven device 82 guides a window glass 81 to which the other ends of the above wires 41, 42 are fixed so that the wire 41 extends in the closing direction of an arrow C and the wire 42 extends in the opening direction of an arrow D respectively. The driving device 80 possesses a housing 1. A worm wheel 5 is rotatably contained in the housing 1. A worm 11 is arranged to be meshed with the worm wheel 5 and is driven by the motor 10. The motor 10 is arranged so that an axis of the motor 10 locates on a center plane 9 of the worm wheel 5; the center plane 9 being perpendicular to a rotaional axis of the worm wheel 5. The pulley 6 is arranged concentrically at a side surface of the worm wheel 5 through a means for transmitting torque. In the conventional device shown in FIG. 6, the worm wheel 5 and the pulley 6 are directly connected, whereby the torque is transmitted from the worm wheel 5 to the pulley 6 through a connecting member.
Total thickness of such a conventional driving device depends on not only a thickness To which is a total of thicknesses of the pulley 6, the worm wheel 5, and the like, but also at least a half of the thickness t of the motor 10, since the worm wheel 5 is fixed or connected through the means for transmitting torque to one side surface of the pulley. Therefore, the conventional driving device has a disadvantage that the whole thickness of the driving device becomes very thick and bulky. Also, in the driving device, there is another disadvantage that the fixing of the device to a door panel, or the like is complicated, since the motor 10 projects from the side surface of the device.
Further, when a shock absorber (not shown in FIG. 6) is provided with the means for transmitting torque in order to change smoothly the rotational motion of the motor 10 into the linear motion of the wires 41, 42, for protecting a window glass 81 and the motor 10, or when the pulley 6 comprises two parts around which each wire 41, 42 is wound respectively, and a one-way-clutch means such as a set of ratchet teeth is provided between the two parts (shown in FIG. 6 by two-dot-chain lines), there occures a problem that the thickness of the driving device increases.